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Entropy of thermal quasiparticles in nuclei

M. Guttormsen·M. Hjorth-Jensen·E. Melby·J. Rekstad·A. Schiller·S. Siem
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Abstract

Information on level density for nuclei with mass numbers A = 20 - 250 is deduced from discrete low-lying levels and neutron resonance data. The odd-mass nuclei exhibit in general 4 - 7 times the level density found for its neighboring even-even nuclei at the same excitation energy. This excess corresponds to an entropy of approx. 1.7 k for the odd particle. The value is approximately constant for all mid-shell nuclei and for all ground state spins. For these nuclei it is argued that the entropy scales with the number of quasiparticles. A simple model based on the canonical ensemble theory accounts qualitatively for the observed properties.

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M. Guttormsen, M. Hjorth-Jensen, E. Melby, J. Rekstad, A. Schiller, S. Siem. 2000-08-28. Entropy of thermal quasiparticles in nuclei. https://doi.org/10.1103/physrevc.63.044301

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